Boomerang



H. R. REDKA v BOOMERANG Filed oct. '7. 1955 June 10, 1958 INVENTOR 135mg If fied/Za ATTORNEY United rates Patent 2,838,310 BooMERANG Henry Redka,INeW York, Y assignor of one-half to Albert K. Roemermann, Jr., Mount Vernon, N. Y.

Application October 7, 1955, Serial No. 539,199

1 Claim. (Cl. 273-106) The present invention relates to boomerangs and more particularly to a methodk and means for controlling and varying the flight path of a boomering according to predetermined gures by means of simple adjustments.

The term boomerang is used in this specification and the claim to define a projectile having two or more blades curved or otherwise shaped in such a manner to serve as airfoils so that whenkthe boomerang isrprojected into the'air with a combination of linear and rotary motion, the rotary motion of the blades produces a force opposing the attraction of gravity, thus tending to sustain the flight of the boomerang by retarding its fall toward earth.

One well known type of boomerang consists of two blades joined together at one end of each at an angle with one another so that the assembled blades have a generally curved or crescent shape. Such al boomerang may be formed from a single piece of material and thus may be considered to have only one curved blade, however for the purposes of this disclosure and claim this type of boomerang will be designated as a two-bladed boomerang with the curved portion on each side of the middle being considered a separate blade.

When properly constructed and skillfully projected, such a boomerang will describe a curved flight terminating at or near the point of origin. It has been found,

however, that such a boomerang is relatively difficult to produce because of the precision required inthe proper shaping of the airfoils and in the curving thereof. In addition, the use of these boomerangs is limited dueto the high degree of skilled required to handle them. The flight paths of thisknown type of boomerang rare also very limited when they are used by a person having only ordinary skill. Y

Accordingly,` it is an object of the present invention to provide an improved boomerang which will be inexpensive and easy to manufacture and to use.

Another object of the present invention is to provide a boomerang which is easily adjusted to be projected in' novel and varying flight paths.

Another object ofthe present invention is to provide a boomerang which is simply manipulated so that it may afford instruction and amusement to children. j Another object of the present invention is to provide a boomerang which is adaptable in all sizes, for easy control in use.

Another object of the present invention is to provide a boomerang which is easily and inexpensively manufactured so that it may be made in give-away models as a prize or premium.

Another object of the present invention is to provide a boomerang which is adapted to be folded or disassembled to facilitate shipment or storage.

Another object of the present invention is to provide a boomerang having an audible signal combined therewith which is automatically operative during the flight of the boomerang.

Another object of the present invention is to provide a boomerang suitable for night use.

" ice Another object of the present invention is to provide a boomerang having a, plurality of blades or airfoils interconnected in an angularly disposed pattern and in which the angular disposition of the blades may be adjusted to provide for different flight paths.

Other and further objects. of the invention will be obvious upon an-understanding of the illustrative embodiment about to be described, or will be indicated in the appendedy claim, and various advantages not referred to herein will occur tok one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part ofthe specification, wherein:

Fig. l is a perspective view of a boomerang according to the invention being held ink launching position;

Fig. 2 is a plan view of a boomerang according to the invention; n

Fig. 3 is a front view of the boomerang of Fig. 2;

`Fig. 4 is a sectional view taken along the line 4-4 of Fig. 3;

Fig. 5 is a perspective view of an elastic weight;

Fig. 6 is a plan view, partially cut away, of another embodiment of the boomerang of Figs. 1 and 2 in which a removable .connector is used to fasten the boomerang blades or airfoils together;

Fig. 7 is a sectional view taken along the line 7-7 of VFig.l 6; and

` Fig. 8 is a sectional view of a whistle attachment for theboomerangs of Figs. 1 and 6.

vReferring to the drawings, and more particularly to Figs.pl3, a boomerang 1 is shown having blades. or airfoils 2 and 3 which are joined together at 4 at a slight angle to form the generally C-shaped or conventional boomerang shape. The airfoils 2 and 3 ofthe boomerang may be formed of any suitably rigid and shatterpr'oof material such as wood or plastic, but preferably they are made of a relatively light material, since, as will be more fully described below, the addition of weights is used to provide a means of controlling the light path of the boomerang. Balsaywood has proven to be one suitable material for the airfoils. The cross section of the boomerangairfoil is preferably rounded to give the boomerang lift as it spins through the air after being launched. This shaping need not be of a high order of precision and a lift effect is obtained when the edges 7 and 8 are rounded and the top surface 9 is given a convex shape as contrasted with a generally flat bottom surface 1i).

Fig. 1 shows two weights 5 positioned on the airfoils. These weights S are used to change the flight path of the projected boomerang'to compensate for any irregularities in the initial manufacture of the boomerang as well asl to allow for the alteration of the natural flight path of the .boomerang into a variety of different and interesting variations. Thus, for example, if the boomerang exhibits insufficient climb and therefore falls to the ground before it returns to a desired point, displacement of one or both of the weights 5 outwardly toward the tips 13 of the boomerang airfoils will increase the energy of rotation originally imparted to the boomerang at its launching to increase and prolong the lifting eiect of the airfoils 2` and 3 and therefore increase4 the length 'of the ight path. Displacing one weight 5 inwardly and the other weight 5 outwardly will change thefrotational trim of the boomerang and will-change the shape of its curving flight path. Various different positions of the weights 5 may be tried by the us'er for each particular boomerang to obtain a variety of llight paths of different altitudes and curvatures. As seen in the drawing, an vindi'ces or scale indicated at 6 is preferably provided on each of the airfoils. These indices 6 aid in the positioning of the weights so that once a particular weight distribution has been found to give a desired ight path, the user may duplicate the position at a later time. Preferably the scales on each of the airfoils differ from one another so that the weight positions on each of the airfoils may be kept track of. This is desirable since slight unintentional differences in the shapes of airfoils 2 and 3, for example, may cause a distribution with one weight at A and the other at 3 to give a different flight path from the apparently similar distribution of one weight at C and the other at 5.

Fig. 3 shows a preferred way of forming the boomerang from separate airfoils. ln this embodiment, the two foils 2 and 3 are overlapped and joined together at their larger ends. This provides a simple construction in which the two airfoils are made essentially identical except for the shape at the point of connection 4 where they are cut with opposite edge angles. This form is especially suitable where an inexpensive boomerang is constructed of a light wood, such as balsa wood. Where the boomerang is molded, it may be made in a single curving piece.

Figs. 6 and 7 lshow another embodiment of the boomerang in which a removable fastener 11 is used to attach two blades or airfoils 12 and 14 together. A boomerang having its blades attached by such a removable fastener may be shipped to the user in a folded or disassembled manner so that the over-all size of the folded or disassembled boomerang is very little larger than the size of a single airfoil of the boomerang. Thus, the boomerang may be shipped with the fastener 11 removed and the blades 12 and 14 overlapped and fastened together. The user assembles the boomerang by placing the airfoils 12 and 14 in their desired position and thereafter inserting the fastener 11. When the airfoils 12 and 14 are fastened together, the fastener 11 may be tightened to permanently lock the airfoils 12 and 14 in a given angular relationship or it may be tightened just enough to cause the airfoils 12 and 14 to remain in a given angular relationship during normal usage while allowing the angle between them to be changed by subjecting them to a greater adjusting force. With such an adjustable boomerang, the user may vary theright path characteristics of the boomerang by changing the angular relationship between the blades. A preferred form of simplified fastener 11 is shown in Figs. 6 and 7 which comprises the well known type self-locking rivet having outer and inner portions 15 and 16, respectively. In order to fasten such a self-locking rivet, the inner portion is inserted into the apertures 17 in the airfoils 12 and 14 through one side of the boomerang and the outer portion 15 is inserted into the aperture 17 from the other side of the boomerang and over the inner portion 16 of the self-locking rivet. The top and bottom of the assembled self-locking rivet are now squeezed, causing the inner portion 16 to bulge tightly within the outer portion 15 and to tightly interlock therewith. The self-locking fastener may be squeezed to the point where its inner and outer portions 15 and 16 tightly lock boomerang airfoils 12 and 14 together to permanent- `ly lock them into position or it may be squeezed only enough to fasten the boomerang airfoils 12 and 14 together to a degree allowing them to be adjusted by the exertion of a reasonable amount of force. A self-locking rivet of this type is easily applied and adjusted and at the same time is not loosened by the rotation and jarring action to which a boomerang such as that described is normally subjected during its flight. Other types of fasteners may be used, such as screw-threaded fasteners. As indicated at 18 in Fig. 6, decorative coatings may be applied to the boomerang airfoils to form colorful or identifying patterns on the boomerang both at rest and in ight. Such coatings may be regular paint mixtures or they may may be luminescent paint, which gives an extremely bright pattern both by day and by night. Both the regular paint -and the luminescent paint patterns on the boomerang airfoils, such as the stripe indicated at 18 on airfoil 14 of Fig. 6, provide spectangular decorative and identifying patterns due to the rotational motion of the boomerang in its normal manner of flight. A luminescent stripe such as that shown at 18 of airfoil 14 provides a glowing circle when a boomerang decorated in this manner is launched at night. The indices or scales on the airfoils indicated at 6 in Figs. l and 2 may also be used to provide a decorative effect in addition to their weight-locating function by being applied in colorful paint patterns or by being formed of a luminescent material.

Although any suitable detachable weight may be used, a preferred embodiment of the weight 5 comprises a relatively thick elastic band such as is shown in Fig. 5. This type of weight is easily applied or moved and remains in position when applied, and is soft and elastic so that it does not add an objectionably hard or sharp element to the boomerang airfoils 2 and 3.

Another embodiment of a detachable weight is shown in Figs. 3 and 8. This Weight comprises a suitable heavy elastic band 20 having a whistle 21 attached thereto. The whistle may be attached in any suitable manner to the rubber band 20, however in the preferred form, the whistle is attached by cutting an aperture 22 in the rubber band and by inserting a grommet-like portion 24 of the whistle into the aperture 22. This weight may be used in the same manner as the weights 5 discussed above, and when it is positioned on a boomerang, it provides a clearly audible whistling sound as the boomerang spins through the air. The whistle may be attached to the boomerang in other suitable-ways. For example, it may be permanently attached by glue or other means to the airfoils without the rubber band 20.

The boomerang is launched in the normal manner by throwing it or flicking it into the air in front of the user. Preferably the boomerang is held in the hand as shown in Fig. 1 with the grip on one end with the flat side away from the thrower and with the point in the air. Other means of launching the boomerang may be used as long as it is projected into the air so that it has forward speed and a rotational or spinning motion. For example, the boomerang may be launched with the aid of au elastic band or catapult. Thus the elastic band is looped over the end of one of the airfoils and it is stretched with one of the users hands while he firmly grasps the boomerang by another airfoil. While the elastic remains in its stretched condition, the users grip on the boomerang is quickly released allowing the elastic band to catapult the boomerang into the air with a rapid spinning movement. As noted above, anything which tends to increase the energy of rotation either in the weight arrangement or in the launching will increase the lift effect in the boomerang flight.

The addition of the weights and the weight location indicator together with the angular adjustment of the airfoils to the boomerang provides an improvement in the boomerang operation which makes the boomerang useful as a toy or sporting article for persons who otherwise lack the training or skill to use such a device. It thus opens up this sport to a wide range of users who will be entertained, stimulated and educated by the experiments which they may easily and successfully conduct with the boomerang. The addition of the weights and airfoil adjustments simplifies the use of the boomerang to the point where an otherwise relatively difcult act of launching is made easy for both adult and child with a minimum of little practice. The scales or indices added to the boomerang airfoils combine with the weights to allow the control of the boomerang flights in predetermined and duplieable flight paths. The use of the weights also simplies the construction of the boomerang by making easy corrections available to offset minor variations in the boomerang construction which occur in mass produced articles of this general nature. A boomerang is thus provided which can be easily and quickly manufactured by unskilled labor so that it may be sold for low prices and widely distributed to a large market. The ability to control the boomerang of the invention also makes it adaptable for use in small spaces or indoors.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

A toy boomerang comprising the combination of a plurality of airfoils connected together in substantially coplanar angular relationship and adapted to support the toy boomerang in aerial tlight when the toy boomerang is projected into the air with combined linear and rotary motion, elastic bands encircling and frictionally engaging said airfoils and adjustably positionable lengthwise of said airfoils to shift the center of gravity of the toy boomerang to change its path of iiight, and indicia on said airfoils for indexing the position of said adjustably positionable elastic bands lengthwise of said airfoils.

References Cited in the le of this patent UNITED STATES PATENTS 477,748 Emerson .Tune 28, 1892 532,233 Faxon Jan. 8, 1895 692,608 Bristow Feb. 4, 1902 FOREIGN PATENTS 188,188 Great Britain Nov. 9, 1922 718,215 Great Britain Nov. 10, 1954 

